Casting Speed
Casting speed is the time it takes for a spell to take effect. Some spells are "instant" and take effect immediately. Some spells are "channeled" and have their effects occur over the duration of the cast. Others take effects after a specific "cast time" with typically more powerful spells having longer cast times. Your casting speed affects the cast time of your spells. It is determined by several factors. The base "cast time" is specified in the spell. Most classes have talents which can reduce the cast time of a spell (eg. Light's Grace and its effect on Holy Light), a class of spell (eg. Divine Fury), a school of spell (eg. all holy spells), or all spells in general (eg. Martyrdom and the Focused Casting effect). Additionally some classes have spells which temporarily reduce the cast time of subsequent spells (eg. Nature's Swiftness). Spell haste is calculated based on modified casting speed, i.e. with the Bane talent for warlocks, the spell haste would be calculated with 2.5 second Shadowbolts rather than 3 seconds. Finally, certain items provide a "spell haste" bonus or a "spell haste rating" bonus. Spell haste rating is used to determine the characters spell haste bonus. At level 70, 15.7 (as of 2.2) points of spell haste rating grants 1% spell haste bonus. Certain debuffs (eg. Curse of Tongues, Mind-numbing Poison) can decrease your casting speed. Taking damage while casting may increase your cast time and there by decrease your cast speed. Notes Because of the general global cool down on spells of 1.5 secs, spell haste effectively has a cap on it for casters. However, spell haste will still reduce the actual time spent casting which can be advantageous when dealing with spell push back or trying to avoid interrupts. Spell haste will also reduce the amount of time before the first cast takes affect, which is very advantageous in the opening of duels, or in situations calling for sporadic (but quick) healing. Channeled spells are effected by haste and will see a reduction in their time spent channeling the spell but no change in overall damage, resulting in a DPS boost. Additionally haste scales at the same rate for channeled spells and spells with a standard cast time. Casting speed calculation New Casting Time = 1 / (Speed% * (1 / Base Casting Time)) or New casting time = Base Casting Time / Speed% or New Casting Time = Base Casting Time / (1 + (Spell Haste Rating/1570)) This may seem counter intuitive at first. Speed is not the same thing as casting time. Speed is a measurement of casts per second, while casting time is seconds per cast. Haste is a multiplier applied to speed, in exactly the same way mounted speed is calculated. That means if you have 10% haste, your speed is 110%. In order to correctly calculate the new casting time, it must be inverted (giving you the spell's speed), multiplied by your speed %, and then inverted again (giving you the spell's new casting time.) Another way to think of it is like this: 1% haste means you will cast 1 additional spell in the time it would normally take to cast 100 spells. If your spell is a 3 second cast, that means you cast 101 spells in 300 seconds, or 2.97 seconds per spell. If you know how long cast you'd like a given sequence of spells to take, you can use the reverse forumla, where Base Casting Time is the sum of all the spells in the given sequence: '''Spell Haste Rating = 1570 * ((Base Cast Time / New Cast Time) - 1) Example: I want my Fireball (3s), Fireball (3s), Scorch (1.5s) to take 6.5 seconds. 1570 * (1 - (7.5 / 6.5)) = ~242 Spell Haste Rating. Note: Blizzard rounds to 4 significant digits. Improving casting speed Various sources that improve casting speed are listed on the Casting Speed improving items page. Note: Haste rating stacks additively with itself but haste stacks multiplicatively. That means that if you have 157 haste rating, you will have +10% haste, no matter how many sources and items that haste rating comes from. If you then use troll Berserking for +30% haste, you would have 110% * 130% = 143% haste. Losing casting speed '''Chance of Ignoring Spell Interruption When Damaged = 100% - Chance to Be Interrupted By Damage The chance to have your spells delayed by damage is additive. If you have a talent for 70% chance to avoid spell interrupts, and a paladin with concentration aura (another 35%) is in your party, you will not receive any spell interrupts from damage. See also *Haste External links *Elitist Jerks Mechanic Primer - Haste - How it works, and what that means Category:Game Terms Category:Combat Category:Formulas and Game Mechanics